What causes headaches? - Dan Kwartler

譯者: Lilian Chiu 審譯者: Helen Chang

In ancient Greece, headaches were considered powerful afflictions.

在古希臘，頭痛 被認為是強大的折磨。

Victims prayed for relief from Asclepius, the god of medicine.

受害者會向醫神 阿斯克勒庇厄斯乞求減緩痛苦。

And if pain continued,

若痛苦持續下去，

a medical practitioner would perform the best-known remedy—

醫師就會進行 最為人所知的治療──

drilling a small hole in the skull to drain supposedly infected blood.

在頭顱上鑽一個小洞， 排出推測受到感染的血液。

This dire technique, called trepanation,

這種可怕的技術叫做 「環鑽術（環鋸術）」，

often replaced the headache with a more permanent condition.

它通常是用更永遠的損傷 來取代頭痛。

Fortunately, doctors today don’t resort to power tools to cure headaches.

幸運的是，現今的醫生不需要 用強力的工具來治療頭痛。

But we still have a lot to learn about this ancient ailment.

但對於這項古老的病痛， 我們仍有很多要學習。

Today, we’ve classified headaches into two camps—

現今，我們將頭痛分為兩類──

primary headaches

原發性頭痛，

and secondary headaches.

及次發性頭痛。

The former are not symptomatic of an underlying disease, injury, or condition;

前者沒有其他潛在疾病、 傷害，或症狀的徵兆；

they are the condition.

頭痛本身就是症狀。

But we’ll come back to them in a minute

我們馬上就會再回來討論它，

because while primary headaches account for 50% of reported cases,

因為，雖然有記錄的頭痛病例中 有一半是的原發性頭痛，

we actually know much more about secondary headaches.

但我們其實對 次發性頭痛的了解更多。

These are caused by other health problems,

次發性頭痛是由其他健康問題所致，

with triggers ranging from dehydration and caffeine withdrawal

觸發的原因很多， 從脫水和咖啡因戒斷，

to head and neck injury,

到頭、頸部的傷害，

and heart disease.

到心臟疾病都有可能。

Doctors have classified over 150 diagnosable types,

醫生分出了超過 150 種 可診斷出的類型，

all with different potential causes, symptoms, and treatments.

每種都有不同的潛在成因、 症狀，及治療方式。

But we’ll take just one common case —a sinus infection—as an example.

但我們只用一個常見案例 來當例子──鼻竇感染。

The sinuses are a system of cavities

鼻竇是一個腔室的系統，

that spread behind our foreheads, noses, and upper cheeks.

位在我們的前額、鼻子， 及上臉頰後方。

When our sinuses are infected,

當我們的鼻竇被感染時，

our immune response heats up the area,

我們的免疫反應 會使該區域溫度上升，

roasting the bacteria and inflaming the cavities well past their usual size.

烤死細菌，並讓腔室發炎， 變得比平時的尺寸更大。

The engorged sinuses put pressure on the cranial arteries and veins,

充血的鼻竇會對 顱動脈及靜脈施壓，

as well as muscles in the neck and head.

亦會對頸部及頭部的肌肉施壓。

Their pain receptors, called nociceptors, trigger in response,

它們的痛覺受器， 即傷害性感受器，就會被觸發，

cueing the brain to release a flood of neuropeptides

發出訊號給大腦， 要它釋放大量的神經肽，

that inflame the cranial blood vessels, swelling and heating up the head.

那就會造成顱內血管發炎， 使頭部發熱腫脹。

This discomfort, paired with hyper-sensitive head muscles,

這種不舒適感，再搭配上 高度敏感的頭部肌肉，

creates the sore, throbbing pain of a headache.

就會造成頭痛的痛感及陣陣抽痛。

Not all headache pain comes from swelling.

並不是所有的頭痛都源自腫脹。

Tense muscles and inflamed, sensitive nerves

緊繃的肌肉以及發炎的敏感神經

cause varying degrees of discomfort in each headache.

會在每次頭痛中造成 不同程度的不適感。

But all cases are reactions to some cranial irritant.

但所有案例都是對於 某種頭部刺激所產生的反應。

While the cause is clear in secondary headaches,

雖然次發性頭痛的原因很清楚，

the origins of primary headaches remain unknown.

但原發性頭痛的原因則仍然未知。

Scientists are still investigating potential triggers

科學家仍在調查 哪些因子可能會觸發

for the three types of primary headaches:

以下三種類型的原發性頭痛：

recurring, long-lasting migraines;

反覆發作且持久的偏頭痛；

intensely painful, rapid-fire cluster headaches;

一連串強烈疼痛的叢發性頭痛；

and, most common of all, the tension headache.

及最常見的張力性頭痛。

As the name suggests,

從名稱就可以知道，

tension headaches are known for creating the sensation

張力性頭痛為人所知的狀況

of a tight band squeezed around the head.

就是彷彿頭部被緊繃的帶子 纏繞用力擠壓的感覺。

These headaches increase the tenderness of the pericranial muscles,

這類頭痛會增加顱周肌的柔軟度，

which then painfully pulse with blood and oxygen.

顱周肌就會隨著血液及氧氣 產生痛苦的搏動。

Patients report stress, dehydration, and hormone changes as triggers,

病人所回報的觸發因子包括 壓力、脫水，以及賀爾蒙改變，

but these don’t fit the symptoms quite right.

但它們不會很符合症狀。

For example, in dehydration headaches,

以脫水所引發的頭痛為例，

the frontal lobe actually shrinks away from the skull,

額葉其實會緊縮而遠離頭骨，

creating forehead swelling

造成額頭腫脹，

that doesn’t match the location of the pain in tension headaches.

並不符合張力性頭痛的疼痛位置。

Scientists have theories for what the actual cause is,

對於真正的成因，科學家有套理論，

ranging from spasming blood vessels

成因範圍從血管痙攣，

to overly sensitive nociceptors,

到過度敏感的傷害性感受器都有，

but no one knows for sure.

但沒人能肯定確切的原因。

Meanwhile, most headache research is focused on more severe primary headaches.

而大多數關於頭痛的研究都把 焦點放在較嚴重的先發性頭痛。

Migraines are recurring headaches, which create a vise-like sensation on the skull

偏頭痛是反覆性的頭痛， 造成頭骨有被鉗住的感覺，

that can last from four hours to three days.

持續時間從四小時到三天都有可能。

In 20% of cases, these attacks are intense enough

在 20% 的案例中， 此類症狀的襲擊很強烈，

to overload the brain with electrical energy,

強到足以讓大腦中的電能過載，

which hyper-excites sensory nerve endings.

電能會使感覺神經末梢極度興奮。

This produces hallucinations called auras,

這就會產生幻覺，稱為預兆，

which can include seeing flashing lights

包含看到閃光

and geometric patterns and experiencing tingling sensations.

及幾何圖案，還有感受到刺痛感。

Cluster headaches, another primary headache type,

叢發性頭痛是另一類的先發性頭痛，

cause burning, stabbing bursts of pain behind one eye,

它會造成單眼後方有 灼熱刺痛的疼痛感，

leading to a red eye, constricted pupil, and drooping eyelid.

導致紅眼、瞳孔收縮， 以及眼皮下垂。

What can be done about these conditions,

我們能如何處理這些

會嚴重影響許多人生活品質的症狀？

which dramatically affect many people’s quality of life?

Tension headaches and most secondary cases

張力性頭痛及大部分次發性頭痛案例

can be treated with over-the-counter pain medications,

都可以用無處方的止痛藥來治療，

such as anti-inflammatory drugs that reduce cranial swelling.

比如能減輕頭部腫脹的消炎藥。

And many secondary headache triggers,

次發性頭痛的許多觸發因子，

like dehydration,

比如脫水、

eye strain,

眼睛疲勞，

and stress,

以及壓力，

can be proactively avoided.

都可以主動避免。

Migraines and cluster headaches are more complicated,

偏頭痛及叢發性頭痛比較複雜，

and we haven’t yet discovered reliable treatments that work for everyone.

我們尚未發現對每個人 都有效的可靠治療方式。

But thankfully, pharmacologists and neurologists are hard at work

但，謝天謝地，藥理學家 及神經學家仍在全力以赴，

cracking these pressing mysteries that weigh so heavily on our minds.

試圖破解這些在我們腦袋中 如此有份量的迫切謎團。